Smorphs at MIT
This is just a guess, but odds are that most consumers won't want to buy a pre-dented car, even if it does improve fuel economy. The thing is, dimples only lessen wind resistance in some situations. In other situations, a smooth skin is preferable. Just like your own skin, a smart morphable surface can adjust to the conditions around it.
Think of smorphs like balloons: When you blow a balloon up, its surface becomes smooth and tight. However, if the volume of the air inside the balloon changes — say because of a leak or a change in the air temperature — the surface of the balloon becomes soft and pliable. In the case of the smorphs, which scientists hope will improve the aerodynamics and fuel efficiency in cars, they would get wrinkly. Those wrinkles could be a big help when it comes to building more efficient cars.
Changing from smooth to dimpled covers the "morphability" component of smart morphable surfaces, but the "smart" part of the name is a key component, too. When you're cold, you don't have to tell your skin "it's time to get goose bumps." It knows what to do based on the conditions it's facing. Smorphs work the same way. They react to the conditions they face to make the most aerodynamic surface.
Researchers at the Massachusetts Institute of Technology have created silicone-based smorphs that react to conditions and lessen the air drag they face by becoming dimpled or smooth. To make the dimples, researchers depressurize the inner space of the smorph. The smorph reacts to the change in interior volume, like skin on someone who suddenly lost his or her beer belly, by forming a pattern of wrinkles and dimples. When the interior volume is increased, the smorph smooths out.
On a car, sensors, a computer and software could be connected to the vehicle's outer skin, checking drag measurements and adjusting the skin's characteristics as needed to reduce resistance and improve fuel economy.